Accounting Policies and Supplemental Disclosures - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for interest on debt, net of capitalized interest	$ 249	$ 266	$ 1,008	$ 1,215	$ 1,651	$ 2,002
Cash paid for operating leases	4,155	2,940	11,475	9,116	14,700	11,882
Cash paid for interest on finance leases	76	71	219	217	289	291
Cash paid for interest on financing obligations	52	47	159	161	217	207
Cash paid for income taxes, net of refunds	1,136	2,004	6,774	8,162	10,920	12,359
Assets acquired under operating leases	5,057	3,571	13,999	11,235	18,188	14,212
Property and equipment acquired under finance leases, net of remeasurements and modifications	977	186	1,968	409	2,413	620
Increase (decrease) in property and equipment acquired but not yet paid	$ 3,341	$ 1,622	$ 4,849	$ 4,793	$ 7,095	$ 4,769